Types of Teeth- Names, Number, Structure & Functions

Types of teeth: There are four types of teeth in humans that perform the functions of chewing, grinding, mixing, etc. The four different types of teeth are Incisors, Canines, Premolars, and Molars. During the course of your lifecycle, you develop two different sets of teeth, that is Milk teeth and Permanent teeth. As a baby, your milk or primary teeth consist of 20 in number. Over a period of a lifetime, they replace permanent teeth which are 32 in number. There are four different types of teeth that will erupt over your lifetime and each will have a different shape and a different function.

Different Types of Teeth

The process of taking food inside the body is called as ingestion. It is broken down mechanically into small pieces before it is finally swallowed. This mechanical process is done by the hardest part of the body which is rich in calcium, such part is called as teeth. There are four different types of teeth that perform different functions such as cutting, grinding, crushing, tearing, etc. Each tooth is embedded in a separate socket and the food is broken and mixed with saliva to form a bolus which is then taken inside the body.

Humans have teeth that vary from each other in shape, structure, and numbers. This arrangement of teeth is expressed through a special formula which is called Dental Formula (expressed in the form of a fraction). The teeth is the hardest part of human body. It is mainly fabricated of proteins (collagen) and minerals (calcium). An adult has 32 teeth but sometimes it may also include Wisdom teeth also called as Third Molar. The different types of teeth are

1. Incisors,
2. Canines,
3. Premolars,
4. Molars.

Incisors

Incisor teeth are located at the front part of the mouth. They are four of them in upper jaw and four in your lower jaw. Incisors are shaped like small pieces of blade. There sharp edges helps to bite the food properly. Incisors are usually the first set of teeth to blow out appearing at about 6 months old. The adult set of incisors grows in between the ages of 6 and 8.

Canines

Canine teeth are next to the incisors. There are two canines at the top of your mouth and two at the bottom. Canines have a keen and pointy surface for tearing food. The first baby canines come in between the ages of 16 months to 20 months. The upper canines grow first which is then followed by the lower canines. Lower adult canines come out in the opposite way. First, the lower canines blow out through the gums around age 9 and then the upper canines come in at age 11 or 12.

Premolars

Premolars  are next to canines. They are four of them premolars on the upper jaw, and four of them at the lower jaw. Premolars are bigger than canines and incisors. They have a flat surface of the teeth are with ridges for crushing and grinding food into smaller pieces to make it easier to swallow. Baby molar teeth are replaced by adult premolars over the time. 

Molars

Molars are the biggest and strongest part of our teeth. They are six of them on the top and six on the bottom. The large surface area of molars helps the food to grind properly. At the time when food is taken into the mouth, your tongue pushes food to the back of your mouth. Then, molars further break up the food into pieces small enough for you to swallow. 

Number of Teeth 

As the baby is born he is toothless as his primary source of food is  mother's milk . As he starts to wean, milk teeth gradually start to appear. Milk teeth later get replaced by permanent teeth by the time the individual turns six years old. Among the four types of teeth, the lower incisors which are the first primary teeth to develop among the kids will in total have 20 primary teeth at the age of 3 yrs, which includes:

• Eight incisors – Four incisors in the upper jaw and four incisors in the lower jaw.
• Four canines – Two canines in the upper jaw and two canines in the lower jaw.
• Eight molars – Four molars in the upper jaw and four molars in the lower jaw.

Over times as the child grow the primary or milk teeth are replaced by permanent teeth which includes:

• Eight incisors  – Four incisors in the upper jaw and four incisors in the lower jaw.
• Four canines –  Two canines in the upper jaw and two canines in the lower jaw.
• Eight premolars–  Four premolars in the upper jaw and four premolars in the lower jaw.
• Twelve molars- Six molars in the upper jaw and six in the lower jaw. It also includes four wisdom teeth.

Dental Formula For Milk Teeth & Permanent Teeth 

Structure of Teeth

A tooth consists of enamel, dentin, cementum and pulp tissue. The portion of a tooth exposed to the oral cavity is known as the dental crown, and the portion below the dental crown is known as the tooth root( also called as Dental tooth). The dental pulp cavity exists in the center of the tooth, through which the dental pulp, called the nerve, runs. In order to receive an impact on the tooth and to absorb and alleviate the force on the jaw, the surface of the tooth root area (cementum) and the alveolar bone are connected by a fibrous tissue called the periodontal ligament. The tooth is supported by the tissue consisting of the alveolar bone, gums and the periodontal ligament.

• Crown: The crown is the visible part of your tooth.
• Enamel: The enamel is the protective layer on the crown.
• Dentin: The dentin is inside the tooth and is not visible. Still, though, it is the largest part of your tooth.
• Cementum: The tissue covering the surface of the tooth root. It connects the alveolar bone with the tooth by the periodontal ligament. Its hardness is similar to bone.
• Dental pulp: The dental pulp contains nerve endings and blood.
• Dental root: The dental root is under your gums. It anchors your tooth to your jawbone.
• Periodontal ligament: Tissue consisting mainly of the fibrous tissue that connects the tooth root and the alveolar bone. It prevents force applied to the tooth from being directly imposed on the alveolar bone while chewing food.
• Alveolar bone: The jaw bone supporting the tooth; the tooth is planted into this bone. When a large part of the alveolar bone is destroyed by periodontal disease or other causes, the tooth becomes loose.

Functions of Different Types Of Teeth

The primary function of teeth is mastication, which involves the cutting, mixing, and grinding food to allow to form it into a bolus that can be swallowed. The teeth are generally conceptualized as a U-shape, with the bottom of the U representing the front teeth. Below is the detailed function of different types of teeth:

Incisors: The anterior teeth are called incisors, directly reflecting their role in cutting food into smaller pieces without performing any grinding function

Canines: Moving posteriorly, the next tooth is the canine, or the cuspid, which is known as the cornerstone of the dental arch. The canine is considered one of the most important teeth due to its crucial role in jaw dynamics, helping to control how the teeth slide on and off each other. Canine teeth function to tear and puncture holes

Premolars: Posterior to the canines are the eight premolars, four in each arch, which assist in crushing, grinding, and mixing food.

Molars: The large surface area of your molars helps them grind up food. When you eat, your tongue pushes food to the back of your mouth. Then, your molars break up the food into pieces small enough for you to swallow.